ARM: dts: r8a7742-iwg21d-q7: Enable PCIe Controller

Enable PCIe Controller and set PCIe bus clock frequency.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Link: https://lore.kernel.org/r/20200825162718.5838-2-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm/boot/dts/r8a7742-iwg21d-q7.dts

@@ -159,6 +159,18 @@ &pci2 {
 	/* status = "okay"; */
 };
 
+&pcie_bus_clk {
+	clock-frequency = <100000000>;
+};
+
+&pciec {
+	/* SW2[6] determines which connector is activated
+	 * ON = PCIe X4 (connector-J7)
+	 * OFF = mini-PCIe (connector-J26)
+	 */
+	status = "okay";
+};
+
 &pfc {
 	avb_pins: avb {
 		groups = "avb_mdio", "avb_gmii";